Investigation of Differences in Biochemical and Mineral Composition of Urine between Pregnant and Non-Pregnant Crossbred Dairy Cattle

Dairy farmers have been longing for simple and economical methods of early pregnancy diagnosis. Urine based biochemical and mineral assays could be one of those methods, owing to the ease of sample collection and relatively simple and economical assays involved. However, basic information on changes in urinary composition during early pregnancy in cattle is lacking. This study was designed to evaluate the differences in biochemical and mineral composition of urine between pregnant and nonpregnant dairy cattle. Urine samples were obtained from crossbred dairy cows, classified retrospectively as pregnant or nonpregnant (n=12 in each group), based on transrectal palpation and ultrasonography at 60 days post insemination, and assayed for glucose, total protein, calcium, phosphorus, magnesium, iron, zinc and copper. Sampling was done every 3 days beginning on the day of insemination (d 0) until d 27. Analysis of data on concentrations of the various variables between pregnant and nonpregnant cows indicated significant (P 0.05) differences in urinary concentrations of total protein, glucose, calcium, phosphorus, iron, zinc and copper between the two groups at one or more of the sampling days. Moreover, within each group, there were significant differences in concentrations of the studied components across various days of the estrous cycle or pregnancy. Results of the present study indicate marked quantitative differences in biochemical and mineral composition of urine between pregnant and nonpregnant cattle. This information can serve as a basis for devising simple, easytouse and cost effective pregnancy diagnosis kits for use in dairy cattle.